African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6576

Full Length Research Paper

Sources of phosphorus for the establishment of palisade grass (Urochloa brizantha (Hochst. ex A. Rich.) R.D Webster)

Amilton Alves Filho
  • Amilton Alves Filho
  • Federal University of Uberlândia, Institute of Agricultural Sciences, CEP: 38.400-902 Uberlândia, Minas Gerais, Brazil.
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Regina Maria Quintão Lana
  • Regina Maria Quintão Lana
  • Federal University of Uberlândia, Institute of Agricultural Sciences, CEP: 38.400-902 Uberlândia, Minas Gerais, Brazil.
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Reginaldo de Camargo
  • Reginaldo de Camargo
  • Federal University of Uberlândia, Institute of Agricultural Sciences, CEP: 38.400-902 Uberlândia, Minas Gerais, Brazil.
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Marina Alves Clemente
  • Marina Alves Clemente
  • Federal University of Uberlândia, Institute of Agricultural Sciences, CEP: 38.400-902 Uberlândia, Minas Gerais, Brazil.
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Isabel Dayane de Souza Queiroz
  • Isabel Dayane de Souza Queiroz
  • Federal University of Uberlândia, Institute of Agricultural Sciences, CEP: 38.400-902 Uberlândia, Minas Gerais, Brazil.
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  •  Received: 13 April 2016
  •  Accepted: 20 May 2016
  •  Published: 09 June 2016

Abstract

In Brazil, about 80% of the 60 million hectares of pasture are in some state of degradation. Among the causes of this degradation is the lack of investment in liming and fertilization at the time of planting. Phosphorus is especially critical because it stimulates root growth in the establishment phase of forage growth. The objective of the study was to evaluate different sources of phosphorus in the formation of Marandu and Xaraés forages. An experimental design of randomized blocks in a factorial arrangement, 2 x 4, with 5 repetitions was used. Treatments consisted of two cultivars of Urochloa brizantha: Marandu and Xaraés and three sources of phosphorus: triple superphosphate (41% P2O5), natural reactive phosphate (28% P2O5) and organic mineral (4- 14-8) plus the absence of phosphate fertilizer (control). Plant height, stem diameter, chlorophyll A and B content and fresh and dry matter mass were evaluated 60 days after germination. Leaf content was also examined for the following mineral nutrients: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn). The Marandu cultivar was superior to the Xaraés cultivar in terms of height. Among the sources of phosphorus examined, there were no significant differences among organic mineral, triple superphosphate and reactive phosphate, for any of the characteristics considered. All the sources, however, differed from the control. The maximum extraction of soil macronutrients by Urochloa brizantha was, in descending order: the macronutrients K>N>Ca>Mg>P>S and micronutrients Mn>Fe>Zn>Cu. These nutrients, thus, needed to be replaced as they were removed through grazing, to replenish the soil. The sources of phosphorus evaluated were not associated with differences in the leaf contents of Cu, Zn and S. The leaf content of the Xaraés cultivar had higher values of N, P, K, Ca, Mg, S, Mn and Zn in relation to Marandu.

Key words: Forage, degraded area, mineral nutrients, fertilization.